Electrical musical instrument



Aug. 17, 1937. c. KIWUL ELECTRICAL MUSICAL INSTRUMENT 3 Sheets-Sheet 1Filed Dec. 17, 1935 INVENTOR CHARLES KIWUL @lzu W ATTORNEY Aug. 17,1937.

c; KlWUL ELECTRICAL MUSICAL INSTRUMENT 5 Sheets-Sheet 2 I 1 1 I 1 IFiled Dec. 17, 1935 C. KIWUL Aug. 17, 1937.

ELECTRICAL MUS ICAL INSTRUMENT ATTO R N EY Patented Aug. 17, 1937 UNITEDSTATES PATENT OFFICE ELECTRICAL MUSICAL INSTRUMENT Charles Kiwul,Brooklyn, N. Y.

Application December 17, 1935, Serial No. 54,815

27 Claims.

The invention relates to an electrically operated musical instrument ofthe type in which electric generators of the rotative induction typegenerate electromagnetic wave frequencies corresponding to givenfundamental frequencies and to harmonics of the same and for selectivelycombining and translating these frequencies into sound waves to givemusical tones of different loudness, pitch and timbre.

The primary object of the invention is to improve, simplify and torender more efficient musical instruments of the above recited class andparticularly to eliminate foreign noises in the electrically producednotes from the instrument.

In one form of such instrument now known the produced electric currentscontrolling the production of audible fundamentals and harmonics thereofare led a part of their way along individual paths in parallel with eachother and are then combined so as to go over a common path forming theaudible sound generating on the loud speaker circuit and the instrumentplayed by the opening and closing of switches in the output circuitleading to the loud speak-er. Ef-

forts have been made with such an arrangement to filter out the higherfrequencies produced in order to eliminate clicks and other foreignnoises caused by arcing when the different control switches in theoutput circuit are in process of being closed or opened. However theseefforts to silence these arcing noises have not proven successful inpractice. Accordingly, the present invention features an organization ofwave frequency producing agencies which are so cou pled permanently intothe loud speaker circuit as to avoid arcing and the similarobjectionable results now prevalent in known arrangements and at thesame time to obtain the desired control of the resulting note which canbe attained in the illustrated embodiment of the invention hereindisclosed simply by selectively short circuiting out of the loud speakerthose inductive circuits, the particular frequencies or combinations ofwhich are not desired in the resulting note produced by the loudspeaker.

The present disclosure also features certain other additionaladvantages, such for instance as the exclusion of magnetic material fromproximity to the field and armature winding of the several generators tothus defeat generation of any eddy and other undesired currents whichhave heretofore marred the desired purity of tone; the providing ofreadily replaceable and .relatively adjustable armatures, each designedto produce in any desired degree of refinement tones of a particularpitch and timbre and any one of which armatures may be replaced by asimilar armature to provide a different tone; the providing of armatureswhich permit of any 5 desired grouping of wave frequencies to producesome peculiar note or sound; the formation of a rotor which in itsmethod of winding will utilize the entire surface for active inductionand thus tend to form a compact construction as a whole, 10 and theproviding of conveniently actuated mechanism which can be remotelycontrolled from the manual or control keyboard for selectivelyintroducing or removing from the loud speaker circuit some particulartonal quality such, 15 for instance, as the violin effect or any desirednumber of such undesired tones, harmonics or other sono-rous effects.

Various other objects and advantages of the invention will be in partobvious from an inspection of the accompanying drawings and in part 0will be more fully set forth in the following particular description ofone form embodying the invention, and the invention also consists incertain new and novel features of construction and combination of partshereinafter set forth and 25 claimed.

In the accompanying drawings:

Fig. 1 is a plan view looking down upon a part of a complete musicalinstrument illustrating a preferred embodiment of the invention andshowing in heavy lines the electrical connections leading to the fieldwindings and showing in light lines the external parts of the armaturewindings leading to the loud speaker circuit and showing also in lightsolid lines the connection lead- 5 ing to one of the arniatures;

Fig. 2 is a view in side elevation of one of the locking circuitclosers, of which there is one for each armature winding or set ofarmature windings in the instrument and showing symbolically acontrolling stop therefor at the manual or playing station and showingin fine lines the electric connections with one of the sets of armaturesof Fig. 1 and the electric connections between the controlling stop andcircuit closer; 45

Fig. 3 is a vertical sectional view taken transversely of the axis ofone of the generators, taken for instance on the line 3-3 of Fig. 1;

Fig. 4, is a view largely in side elevation of the left hand side ofFig. 3 partly in section along the line l-4 of Fig. 3 and parts brokenaway in vertical section to show some of the block armatures and thearmature windings;

Fig. 5 is an explanatory view showing the wiring of one of thegenerators in its simplest form;

Fig. 6 is a schematic view showing the wiring of three of the generatorseach with its playing key and with four different armature windings andshowing four stop controls, one for each set of the similarly woundarmatures of the three generators;

Fig. 7 is a view partly in section of one of the segmental sidearmatures parallel to the view shown in Fig. 4 and taken on the line llof Fig. 8;

Fig. 8 is a longitudinal sectional view taken on the line 8-8 of Fig. 7;and

:Fig. 9 is a sectional view similar to Fig. '7 of a block form ofarmature.

It will be understood that in the complete instrument there will beincluded a plurality of generators of alternating or pulsating electriccurrents of the frequencies capable of producing the musical scale andthateach generator supplies current to produce a tone of a pitchdifferent from that of every other generator, that is, one generator foreach musical tone included within the scope of the instrument.Altogether in standard makes of such instruments there will beseventy-two to eighty-four such generators used and thus capable ofproducing seventy-two to eighty-four distinct fundamental notes. Thegenerators are grouped into sets for convenience in driving them from asingle shaft and to effect economy in space disposition with each setgeared to a main drive shaft so that they will all have the sameconstant speed, but it is within the scope of the disclosure to driveone or more sets of generators at different speeds and obviously thegenerators will be of different sizes to accommodate the differentwindings necessary to produce the notes of the musical scale.

In the fragmentary showing of one such in- 40 strument disclosed in Fig.1 there are disclosed four generators of which generators l B and ii aredisposed in tandem and have their rotors fixed to an auxiliary orsecondary shaft i2 and another set of generators l3 and it have theirrotors se- 45 cured to an auxiliary shaft l5, both shafts beingconnected through beveled gearing i6 and it with a main drive shaft i8operated from a motor or other source of power.

As the several generators are of similar com 50 struction the detaileddescription of one of them as particularly shown in Figs. 3 and 4 willbe sufiicient for the others. In general each generator includes asupporting frame [9 in which is rotatably mounted a fieldwound rotor 20and 55 a plurality of fixed armatures 2|. The supporting frame I9includes an annular housing ring 22 integral with a wide spreading footor pedestal 23. Two side panels or spiders 2t and 25 are fitted intoopposite sides of the ring 22. These 60 side panels form a bearing forone of the auxiliary shafts l2l5 and which shaft has the rotor 20secured thereto to rotate therewith.

The rotor is provided with a field winding 26 which consists of onecontinuous conductor,

65 wound in one or more layers about the core or winding mounting 21.One end of. the winding 26 is connected to a ring 28 secured to one endof the hub 29 of the core forming part of the rotor. The opposite end ofthe field Winding 70 is secured to a ring 30 secured to the opposite endof the hub. By means of brushes 3| and a conductor 32 engaging ring 28current from a source of electric energy is led through wiringhereinafter described to the ring 28 and by means of 7s brushes 33 and aconductorjfi engaging ring 30 the circuit is completed back to thesource.

The windings of the field rotors illustrated are similar to theconventional ring type armature windings but it is obvious that otherconventional forms of rotor windings are capable of producing the wavefrequencies in the armatures as herein featured. In the instant case,for instance until the entire rotor is wound with the turns of thewindings substantially equidistantly spaced apart and the final turnleads to the ring 30.

;The armatures 2| of each generator are arranged in four parallel planesperpendicular to the shaft l2 and are of two types; one of segmentalform as shown in Figs. 4, 7 and 8 grouped in wheel-spoked fashion asshown in Fig. 4 about opposite sides of the rotor; and the other of.block form as shown in Figs. 1, 4 and 9 grouped about the periphery ofthe rotor. These armatures 2i are adjustably and demountably secured tothe frame I 9. For this purpose the side panels 24 and 25 have theirouter portions each defined by an annular flange 36 from the inner edgeof which projects an integral fiat ring-like outstanding fiange 31. Thetwo outer side sets of armatures 38 of the segmental form are secured bymeans of screws 39 inserted through slots 40 spaced apart in the flange36. This construction permits of a circumferential adjustment of thearmatures as shown in the unequal spacing illustrated in Fig. 4 thusproviding means to regulate the phase of the induced electro-motiveforces. The slots Ml are of slightly greater width than the diameter ofthe screws 39 so that by an axial adjustment as shown in Fig. 3 thearmature may be adjusted to vary the degree of loudness in the finalnote. The intensity of the electromotive force may be varied byintroducing variable resistances in the several field circuits of theindividual rotors as hereinafter noted in discussing Fig. 6. The lengthof the slots 40 are selected to permit the armature assemblies to bemounted so that the current of one assembly or generator may be eitherin phase or out of phase with other similar currents in another assemblyor another generator. Similarly the armatures of the block type 4! aredemountably secured and readily replaceable by means of screws 52engaging on the outstanding flange 31.

The present disclosure features the construction of the rotor cores 21as well as the cores 83 and 44 respectively of the armatures 38 and 4!of non-magnetic material and which preferably, but not necessarily,should be formed of a material which is a non-conductor of electricityto avoid the formation of eddy currents and other.

windings are depressed and this action stops abruptly and completelywhen the keys are released although all of the rotors, or at least thosehaving their associated switches or keys closed are always in motionwhen the instrument is in .i use.

The armatures of each type are of similar construction to others of thesame type except for size and variations in windings as hereinafternoted so that the detailed description of one of 10 each type will applywith the necessary changes in generator windings to every other armatureof the same type. Each armature winding consists of one or a pluralityof individual groups of wind ings designed so that each armature willprol duce a compound set of, wave frequencies and a resulting intensityof sound from the loud speaker different from that, produced by everyother armature.

. In general each generator is designed to pro- 20 duce tones of adifferent fundamental frequency from that of every other generator. Inother words each armature is designed to produce an induced current notonly of the fundamental frequency of the tone which the particularassociated generator is designed to produce but also a set offrequencies which are multiples of the fundamental frequency and thussupply the harmonies necessary to give to the tone its desired timbre.Further the armatures of all generators do or at least all of a set ofgenerators have the same number of sections of like timbre. In Fig. 4for instance, assuming an equal number of armatures on each side of therotor, there are fifteen armatures for that particular generator 35 oneach side face and it can thus produce tones of thirty differenttimbres.

Referring first to one of the side or segmental armatures 38 shown inFigs. 4, 7 and 8 a single wire 45 is wound on the core 43 in such a way40 that it forms a set of inductively active sections connected inseries and arranged so that the electro-motive forces produced in anypart of the winding are all in one direction. The inductively activesections .are shown, to be four in Figs. '7 and 45 8 of which a singlelength of wire indicated at 46forms the fundamental and which length 46extends into a core of two turns as best shown in Figs. 7 to formsection 41, then into three turns to form section 48 and finally into acoil com- 50 prising four turns of wire to form the section 49 so thatthis particular armature is capable of producing four different wavefrequencies, one of which 46 is, as above noted, a fundamental frequencyand the other three are harmonics of 55 the fundamental.

The block type armatures 4| may be wound in one of two ways. Referringto the winding shown in side elevation at the top of Fig. 4, a singleconductor 5|] is wound spirally about the 60 block core 44. It will beunderstood that this winding produces only one wave frequency. Referringto the other type of armature winding as shown in Fig. 9 a conductor 5|is wrapped successively about three sections of a core 44 as 65 shown toform groups of inductively active sections shown at 52, 53 and 54 toproduce respectively the fifth, sixth and eighth harmonics. In theconstruction of these armatures the different windings are each wrappedabout composite 70 sections of the core, the windings are connected inseries and the composite sections are then cemented together into oneintegral block.

From this construction it is seen that when the rotor turns a unitangular distance equal to 75 the angle of distance between two adjoiningarmature coils (alpha) one full cycle of impulse is induced in winding46 which is the fundamental frequency winding for its associatedgenerator and at the same time two cycles are induced in 41, three in48, four in 49, five in 52, six in 53 and eight cycles in 54.

As is particularly shown in Fig. 8 the inductive active sections of thewindings for the fundamental frequency and for the harmonics are shownof different lengths and are differently spaced from the rotor so as toget the proper relative intensity of the induced current to produce atone of a particular timbre which any particular armature is designed toproduce.

All of the windings of all the armatures are connected in series to formone continuous permanently closed output circuit in which is includedone or more loud speakers 55. The windings embedded in or encircling theseveral armature cores are connected one after the other by flexibleconnectors 56 designed to permit the desired spacing of the armatures 38shown in Fig. 4.

Referring to the interconnecting wiring external to and connecting theseveral generators with the loud speaker reference is made to Fig. 5 asan illustration of the simplest form of connection. In this figure thewiring of one of the generators is shown and includes field winding 20connected through a main control switch 5'! with a source of electricenergy herein represented by leads 58 and 59 connected to the source ofdirect current. Inductively associated with the rotor field windings 20are four armatures 6|I-63 connected in series with one end connected bylead 64 to one side of the loud speaker 55 and the other end connectedby lead 65 to the other side of .the loud speaker. The armatures aredesigned to be shunted out of the output circuit selectively by thecorresponding circuit closers 66-69.

From this construction it is seen that with the field winding active anyone or more of the armatures designated generally as 2| andspecificallyas 6|l63 in Fig. 5 may be selectively short circuited out ofthe loud speaker circuit leaving the remaining armatures to impose itsor their particular combination of wave frequencies on the loud speakercircuit, whereby each armature produces its own distinctive set of wavesto act on the loud speaker and to be converted thereby into sonorousvibrations. With all of the circuit closers 66-69 closed, all of thearmatures will impose collectively their respective wave frequenciessimultaneously on the loud speaker circuit. Should it be desired toeliminate any particular tonal effect the db cuit closer governing thearmature which produces that effect is moved into closed position. Forinstance assume that armature 69 produces a violin effect, then byclosing its associated circuit closer 66 the violin effect is removedfrom the resulting notes produced by the loud speaker.

Referring to the more complicated scheme of wiring shown in Fig. 6, allof the armatures for producing the same timbre are connected into agroup which includes the armatures of the same timbre of all of thegenerators and these groups are connected into one continuous outputcircuit. More specifically there is disclosed three generators 10, H and12 which may be, for instance, generators III, II and I3, theirrespective field windings 13', I4 and 15' corresponding to the windings26 hereinbefore described are connected in parallel with the currentsource leads 58 and 59. Control switches 13, 14 and 15 corresponding tothe switch 5! of Fig. 5 permits a selective control operable from themanual or playing station for selectively energizing the field windingsof those generators, the notes of which are desired. It is alsosuggested that variable resistance .16, I! and 18'be inserted in each ofthe field circuits to control the loudness of resulting notes producedby each generator. In this form of wiring, only four armatures areillustrated in Figs. 5 and 6 but four is sufficient to illustrate theprinciple of wiring shown by these figures. The wiring is so .arrangedthat an armature having a certain tonal value, such for instance as thatof the violin, is connected in series with every other armature havingthe same tonal value. Assume for illustration that armature 79 ofgenerator 10, armature 80 of generator ll and armature 8! of generator12 are similarly wound to produce say the violin effect. These threearmatures are connected in series and form part of the output circuit.This particular group of armatures may be short circuited out of theoutput circuit by means of a control switch 82 so that by closingswitch- 82 the violin effect may be removed from the note produced bythe loud speaker. Similar-' 1y each of the other three armatures of eachgenerator is connected in series with the other similarly woundgenerators and are introduced or removed from the output circuit by theselective opening or closing of their associated switches 83, 843 and85. It is suggested that a transformer 86 be included in the outputcircuit with its secondary 87 forming part of the conductor $5 and itsprimary 88 connected by leads 88 and 9d to the assembly of connectedarmatures. Tracing one of the circuits in Fig. 6 for illustrationconductor 90 leads to one end of armature winding 79 and to one side ofthe short circuiting switch 82. The other end of winding 19 is connectedby conductor 9! to one end of armature winding 80. The other end ofwinding 88 is connected by conductor 92 to one end of armature winding8!. The other end of winding 8! is connected by means of conductor 93back to the other side of switch 82. With switch 82 open as shown inFig. 6 the wave frequencies produced by the connected armature windingsi9, 80 and BI are imposed on the output circuit and pass at intersectionpoint 9 into the second set of connected armature windings controlled byswitch 83, then passes at intersection point 95 into the third set ofconnected armatures controlled by switch 84, then passes at intersectionpoint 9% into the fourth set controlled by switch 85 and then throughconductor 89 back to the secondary of the transformer.

From this construction it is seen that all of the armatures arecontained in the output circuit and that this output circuit is free ofany switches or other breaks which heretofore imposed objectionalclicks, static and foreign noises in the notes produced by the loudspeakers; The switches 82-85 simply introduce or remove at will theselected armature windings which are desired in or out of the outputcircuit.

Reference is made to Fig. 2 for a more complte disclosure of any one ofthe circuit closers 66-69 of Fig. 5' or 82-85 of Fig. 6. Assume forinstance that Fig. 2 is a complete showing of switch 56 in Fig. 5. Itwill be understood that these circuit closers which are preferablylocated close to the armatures which they control are in turn controlledat the manual orp-laying station which, not infrequently is forty orfifty feet away from the assembly of the generators. In the showing inFig. 2 a stop at the manual of the console is indicated by the two-wayswitch 97 which is connected to a source of direct current indicated bythe leads 98 and 99. Mounted on a support I are apair of electro-magnetsllll and I02 between which is mounted a slide bar I03 carried inbrackets H15 and at opposite ends of which are armatures I and H18coacting respectively with the electro-magnets Ifll and H12. Mounted onthe support I 00 is afixed contact i0! and mounted on the bar I03 is acoacting movable contact I08. Conductors H19 lead to the electro-magnetill! from one side of the switch 91 and conductors H0 lead from theother side of the switch to the electro-magnet M12. 4

From this construction it will be noted that by pulling the manual stopto shift the switch to the right in the showing in Fig. 2 the circuit iscompleted through the right electro-magnet, the bar N13 with itsassociated armatures is drawn to the right thus moving contact I08 intoa circuit closing engagement with contact l8"! and thus closing itsassociated switch 66. Similarly shifting the manual stop to connect thesource 98-99 with the left electro-magnet ifli will energize the same,and act on armature I05 to shift the rod I83 and with it the movablecontact I08 into its open circuit position shown in Figs. 2 and 5, thusrestoring wiring 68 into the output circuit to contribute its effect onthe loud speaker. It is understood, of course, that there is a circuitclosing arrangement such as shown in Fig. 2 for each of the otherarmature short circuiting switches. In this way the player can introduceand remove at will from the resulting note produced by the severalgenerators those particular sounds which he desires present or removedfor the time being.

As it is difficult at present to make a loud speaker which will produceequally well all frequencies within the audible range, it is suggestedthat instead of using only one loud speaker in the output circuit, abetter practice would be to group the generators into sets of differentpitch producing capacities and to utilize for each set that particulertype of loud speaker best suited for that particular pitch or group ofpitches. Accordingly it may be assumed that in the showing in Fig. 6,for instance, the three generators ill, 1! and i2 and which, as notedbefore, may be regarded as the generators l0, ii and i3 of Fig. 1produce relatively low frequency vibrations and that the associatedloudspeaker is particularly designed to produce the correspondingly lowpitch notes. Likewise it may be assumed that generator id is a symbolicrepresentation of another set of generators capable of producing arelatively high frequency vibration and that this set has a loud speakercorresponding to that shown at 55 and particularly designed to producethe correspondingly high pitch notes.

In operation and assuming that the device illustrated is an organ, thatis a device capable of functioning as does a pipe organ, the player atthe console operates the player keys conventionally and which in turnopens and closes selectively the different circuit closers which controlthe rotary field windings of the different generators as for instance byopening and closing the field switches such as 51, i3, 14 and 15.

Depressing the key which closes control switch- '53, for instance, wouldcause a note to sound which is composed of the four frequenciesintroduced into the loud speaker circuit by the four armatures 7Q, Hi,H2 and H3 (Fig. 6). In this Way a musical piece can be played byconventionally operating the banks of playing keys usually found inconventional forms of pipe organs. As before noted should it be desiredto modify the tonal effect of any note or a group of notes, a stop ofwhich there is one for each similar timbre group, is pulled or pushed tomove a controlling circuit closer, such as 91, into position tointroduce or remove at will the selected timbre group or groups into orfrom the resulting note subsequently played by the manipulation of theplayer keys controlling the switches like 51, l3, l4 and I5.

The instrument is turned on or off by means of a main switch H4 in themain leads 5B59 and the device is preset to give the requisite loudnessand intensity of sound by suitable adjustments of the variableresistances in the field winding circuits.

By means of a device of this character it is seen that the switches orstops such as 66--69 in Fig. 5 o'r 82--85 in Fig. 6 may be opened orclosed without making any break in the output circuit and thereby thereis eliminated the reason Why clicks and static noises have occurredheretofore in similar forms of electrically operated musicalinstruments.

A variable resistance H5 may be included in one of the main supplylines, such as the lead 32 in Fig. 5 so that by varying the resistancethe player can at will cause a fading or a swelling in the volume of thesound produced and in this way vary the intensity or volume of theresulting music.

I claim:

1. In an electrically operated musical instrument, the combination of aplurality of sets of electric generators of the rotor type, eachgenerator provided with a rotor having windings, each set including asecondary shaft for driving the rotors of its associated set, a maindriving shaft geared to the several secondary shafts to drive all therotors in unison, a source of electric energy connected to all of thewindings of the several rotors through a variable resistance interposedbetween the source and the said rotors, a plurality of rotor fieldswitches, one for each generator for controlling the energizing of itsassociated generator, each generator including a plurality of coactingarmatures with each armature having a winding to produce a different setof wave frequencies from that of every other armature in the associatedgenerator, and with a winding of an armature of one generator producingas a component part of its set of wave frequencies the same wavefrequency as is produced by an armature of one or more other generatorsand said similarly wound armatures connected in series, means forming anoutput circuit including a loud speaker and a plurality of circuitclosers, one for each armature and operatively connected to shortcircuit out of the output circuit the'windings of any group of armatureswhich produce the same wave frequency while leaving in circuit theremaining armatures not so short-circuited.

2. In an electrically operated musical instrument, an electric generatorincluding a supporting frame, a shaft mounted for rotary movement in theframe, a rotor secured to the shaft to turn therewith and including acore of non-magnetic material and a winding encircling the core andmeans for connecting the winding to a source of electric energy, aplurality of coacting armatures demountably secured to the frame,grouped about the rotor and encircling the axis of rotation of theshaft, certain of the armatures having a segmental form and disposed intwo planes on opposite sides of the rotor and certain others of thearmatures being of block form and disposed in two planes about theperipheral edge of the rotor, the windings of all of the armatures beingconnected in series, means forming a loud speaker circuit including aloud speaker and said series connected armature windings, a plurality ofcircuit closers, one for each armature for short circuiting itsassociated armature winding out of the loud speaker circuit and aplurality of remote controls, one for each circuit closer forselectively actuating its associated circuit closer and thus control thearmatures removed from the loud speaker circuit.

3. In an electrically operated musical instrument, an electric generatorincluding a supporting frame, a shaft mounted for rotary movement in theframe, a rotor secured to the shaft to turn therewith and including acore of non-magnetic material and a winding encircling the core andmeans for connecting the winding to a source of electric energy, aplurality of coacting armatures demountably secured to the frame,grouped about the rotor and encircling the axis of rotation of theshaft, certain of the armatures having a segmental form and disposed intwo planes on opposite sides of the rotor and certain others of thearmatures being of block form and disposed in two planes about theperipheral edge of the rotor, the windings of all of the armatures beingconnected in series, means forming a loud speaker circuit including aloud speaker and said series connected armature windings, a plurality ofcircuit closers, one for each armature for short circuiting itsassociated armature winding out of the loud speaker circuit.

4. In an electrically operated musical instrument, the combination of aplurality of electric generators of the inductive type, each generatorincluding a rotor having a single winding connected to a source ofelectric energy and each generator including a plurality of fixedarmatures, each armature provided with a group of windings connected inseries and acting to produce its own distinctive set of electric wavefrequencies including a wave of a fundamental frequency and other waveswhich are multiples of said frequency coacting with the fundamental waveto produce a fixed timbre for each armature, the windings of eacharmature being different collectively from that of every other armatureof its associated generator, one winding of one of the armatures of oneof said generators being the same as the winding of one of the armaturesof another generator whereby each of said two armature windings producethe same wave frequency, means for converting the waves from all of thegenerators into sonorous vibrations and a single manually actuatedcontrol for simultaneously connecting to said converting means the saidlast named two windings.

5. In an electrically operated musical instrument, the combination of aplurality of electric generators of the inductive rotor type, meansforming a power circuit including a source of electric energy, the fieldwindings of each of said generators, and a manually controlled variableresistance to control the volume of the resulting sound. from theinstrument, each generator including a plurality of armatures, eacharmature provided with a winding to givea particular resulting note toeach armature different from that produced by every other armature inthe associated generator, and certain of the windingsof differentgenerators producing the same resulting.

timbre effect, means for converting the frequencies from the severalarmatures into sonorous vibrations and a control for simultaneouslyshortcircuiting from said converting means those windings which producethe same timbre eifect from the different generators.

6. In an electrically operated musical instrument, the combination of aplurality of electric generators each including a rotor forming a ro- 10tating field, power means for rotating all of the field forming rotorsin unison, each generator including a plurality of fixed armatures witheach armature wound to produce a combination of wave frequencies ofdifferent degrees of loudness of which one wave frequency is the same inall of the armatures of one generator and each armature having at leastone other wave frequency of the combination being different from thatproduced by each other armature of its associated generator, thewindings of the armature of each generator being connected in series, atransformer having its primary incircuit with said armature windings, aloud speaker permanently in circuit withthe secondary of saidtransformer and control means for selectively short circuiting at willone or more of the armature windings out of the primary of thetransformer.

7. In an electrically operated musical instrument, the combination of aplurality of electric generators of alternating or pulsating currenttype, each wound to produce its own distinctive set of wave frequenciesand each including a rotating field winding and a plurality of fixedarmature windings, means forming aloud speaker circuit permanentlyconnected in series with all of the armature windings and control meansfor removing from the loud speaker circuit the wave frequencies producedby one or more of the armatures while retaining in the circuit thefrequencies produced by all of the armatures remaining in circuit.

8. In a device of the class described, the combination of a plurality ofelectric generators of the inductive rotor type, each generatorincluding a 5 field rotor winding and a plurality of fixed armaturewindings, all of the armature windings being connected in series with aloud speaker, a source of direct current, means connecting the rotorwindings in parallel with said source and a plurality of controlswitches one between each rotor winding and said source.

9. ln a device of the class described, the combination of a plurality ofelectric generators of the inductive rotor type, each generatorincluding a field rotor winding anda plurality of fixed armaturewindings, all of the armature windings being connected in series with aloud speaker, a source of direct current, means connecting the rotorwindings in parallel with said source and a plurality of controlswitches one between each rotor winding and said source and controlmeans for selectively short-circuiting any armature out of serieswithout interrupting the connection of the remaining armature with theloud speaker. 10. In a device of the class'described, the combination ofa plurality of electric generators of th inductive rotor type, eachgenerator including a rotor field winding, and a plurality of coactingfixed armatures connected in series, each generator wound to produce aset of wave frequencies different from the set of wave frequenciesproduced by every other generator, a plurality of playing circuitclosers, one for each field wnding operable in playing the device,control means for selectively short-circuiting any one or more armaturesout of this series circuit thereby to change the set of wave frequenciesof its associated generator and means permanently in circuit with all ofthe armatures for translating the wave frequencies from all of thegenerators for the time being in circuit therewith into sound waves.

11. In a device of the class described, the combination of an electricgenerator of the inductive rotor type including a rotor field includinga winding connected to a source of electric energy and a plurality ofcoacting fixed armatures, each armature provided with a plurality ofwindings connected in series, each of said armatures wound to produce analternating electro-motive force distinct from that produced by eachother armature, mountings for both the field and armature windingsformed of nonmagnetic material to minimize the formation of eddy andother foreign currents in proximity to the field and armature windingsand means for converting the electro-motive force from each armatureinto audible vibrations and each armature acting thereon to produce itsow particular pitch and timbre.

12. In a. device of the class described, the combination of ,an electricgenerator including a rotor having a winding adapted to be connected toa source of electric energy to energize the rotor field, and a pluralityof coacting fixed armatures, each armature divided into fractionalsections and each' section provided with a winding, the windings of eachsection being permanently connected in series and forming anelectro-motive force different from that formed by every other sectionand each comprising a fundamental frequency and a frequency constitutinga harmonic of its associated fundamental frequency, means forming a loudspeaker circuit in series with the windings of all of the armatures andcontrol means for short circuiting out of the loud speaker circuit anydesired number of armature windings.

13. In an electrically operated musical instrument, a generatorincluding a rotor comprising a core of non-magnetic material having awinding connected to a source of electric energy and a plurality offixed armatures inductively associated with the rotor, each armaturecomprising a core of non-magnetic material and having a set of windingsconnected in series and producing a frequency of wave formationdifferent from that produced by each other armature, means providing aloud speaker circuit, the windings of the several armatures being inseries with each other and with the loud speaker circuit and manuallyactuated means for short circuiting at will the wiring of any one ormore 14. In an electrically operated musical instru,-' ment, thecombination of an electric generator of the inductive rotor typeincluding means forming a rotating field having a single windingconnected to a source of direct current electric energy and a pluralityof fixed armatures associated therewith, each armature provided with agroup of windings connected in series of which each winding is differentfrom every other winding of the group and coacts to produce its owndistinctive set of electric waves, the group of windings of eacharmature being, different from the group of windings of every otherarmature whereby each armature produces its own distinctive set of wavesand each armature producing the same fundamental wave together withharmonics of said same fundamental wave, means for converting said wavesinto sonorous vibrations and manually actuated control means forselectively disconnecting any one or more of the armature windings fromsaid last named converting means.

15. In a device of the class described, the combination of an electricgenerator comprising a rotor including a mounting of non-magneticmaterial and a winding therefor comprising a single conductor wound crcularly and uniformally about the entire exposed surface of the rotorthereby to utilize practically the entire surface of the rotor foractive induction and a plurality of coacting armatures encircling theaxis of rotation of the rotor and each armature wound to produce a setof wave frequencies different from the set produced by every otherarmature and certain of the armatures wound to include the samefundamental frequency, the windings of all of the armatures beingconnected in series,

, means forming an electric circuit including an instrument forconverting the wave frequencies of the several armatures into soundwaves, timbre control means including a plurality of circuit closers,one for each armature for selectively introducing and removing anydesired armature winding into and from said electric circuit thereby tocontrol the timbre of the note resulting from the energizing of thearmatures for the time being included in the circuit and playing controlmeans including a circuit closer in the rotor winding for controllingthe energizing of the rotor field and thus controlling the operation ofthe generator.

16. In an electrically operated musical instrument, the combination ofan electric generator of the inductive type including a movable fieldand a plurality of fixed armatures, means forming a closed loud speakercircuit free of switches and other breaks, said closed circuit includinga loud speaker and the windings of the several armatures, each armaturewinding acting to contribute its own peculiar tone to the loud speakereffect and timbre control means for selectively short circuiting out ofthe loud speaker circuit any one or more of the armature windings whilepermitting the balance of the windings to remain in the loud speakercircuit.

17. In an electrically operated musical instrument, an electricgenerator having a rotating field and means forming an output circuitincluding a plurality of fixed armatures coacting inductively with thefield, each armature wound to produce a set of frequencies differentfrom the set of frequencies produced by every other armature, means alsoforming part of said output circuit for converting the wave frequenciesof said armatures into sound waves and a plurality of circuit closers,one for each armature for connecting and disconnecting its associatedarmature at will from said converting means.

18. An electrically operated musical instrument including a plurality ofarmatures each wound to produce a set of Wave frequencies different fromthat produced by the other armatures, means for connecting the armaturesin series to form an output circuit, each of said armatures imposing onthe circuit the combination of wave frequencies generated by thatparticular armature, parts of certain of the armatures being similarlywound and the windings connected togetherin series to produce as acomponent part of said combination the same wave frequency, controlmeans for short circuiting said certain armatures at will out of theoutput circuit, and a loud speaker included in the output circuit.

-19. In an electrically operated musical instrument, the combination ofan alternate or pulsating current generator for producing simultaneouslya fundamental wave frequency and a plurality of secondary wavefrequencies capable of producing a fundamental note and certain of saiddifferent wave frequencies capable of producing a definitetimbre,another similar alternate current generator for producing a fundamentalwave frequency of its own and a plurality of secondary wave frequenciescapable of producing a note different from the first named note, certainof said secondary wave frequencies of the second generator capable ofproducing the same definite timbre, means for converting all of saidwave frequencies into audible sound and a single control means forintroducing and removing at will from said last named means the saiddefinite timbre produced by both of the generators.

20. In a device of the class described, the combination of an electricgenerator including a rotative field provided with windings and aplurality of armatures, each armature wound to produce a different formof compound frequency wave, each compound wave including the samefundamental frequency and one or more multiples of said fundamentalfrequency capable of producing harmonics thereof, and which compoundwaves distinguish from each other in the number of said multiples of thefundamental frequency present and means for translating.

said compound frequency waves into audible .sound.

21. In anelectrically operated musical instrument capable of producingmusical notes of various pitch and timbre, the combination of aplurality of sets of generators, each generator including a rotatingfield winding connected to -a source of electric energy and one or morefixed armatures, the armatures of each generator wound to produce afundamental note and one or more harmonics of the fundamental note, the

windings of the armatures of each set being connected in series, aplurality of loud speakers, one for each set and each loud speakerconnected in series with the armatures of its associated set ofgenerators, and each set of generators wound to produce in itsassociated loud speaker a note having a pitch different from thatproduced by every.other set of generators.

22. In a device of the character outlined, the combination of aplurality of electric generators of the inductive rotor type, eachgenerator including a. rotor core of non-magnetic material and a fieldwinding on the core and a plurality of armatures, each armature formedwith a core of non-magnetic material and an armature winding thereon, aloud speaker, all of said armature windings and said loud speaker beingconnected in series, a source of direct current, said field windings ofthe generators being connected in parallel with each other to saidsource and a plurality of control switches, one for each generator andlocated between the source and the field rotor winding of the generator.

23. An electric generator including a rotor field winding and aplurality of fixed armature Windings, each armature winding being wounddifferent from that of every other armature winding and thus capable ofproducing a wave formation different from that produced by every otherarmature winding, the wave formation caused by each armature windingincluding the same fundamental frequency and one or more multiples ofsaid fundamental frequency and each wave formation distinguishing fromeach other in its capacity to form in the produced note a loudness inone of said multiples different from the loudness produced in another ofsaid multiples and means for translating said wave formation intosonorous notes.

24. In an electrically operated musical instrument, the combination of arotative field and a set of fixed armatures, a field switch for therotative field, each armature of the set being wound differently fromthat of every other armature of that set, means forming a controlcircuit, said means including a control switch, a loud speaker and thewindings of all of the armatures arranged in series and means includinga variable resistance in the circuit which includes the rotative fieldfor controlling the volume of the sound produced by the loud speaker.

25. In an electrically operated musical instrument, the combination ofan electric generator of the inductive rotor type and including a rotorprovided with a field winding and an armature provided with an armaturewinding and a loud speaker connected in series with the armaturewinding, said armature winding organized to cause the loud speaker tosound a musical note the wave produced by each other armature of 10 thatgenerator, control means for selectively energizing the field windingsofany one of the generators and means for translating said compoundfrequency waves into audible sound.

27 --\In a device of the class described, the com- 15 bination of aplurality of electric generators, each generator including a rotativefield winding and aplurality of armatures, each armature of any onegenerator being wound to produce a different form of compound frequencywave from the wave produced by each other armature of that generator,means for selectively grouping together in circuit certain of thearmature windings, a manual for playing the device, said manual providedwith a plurality of manually actuated circuit controlling keys, one forthe field winding of each generator and means for translating saidcompound frequency waves into audible sound.

CHARLES KIWUL.

